Low wattage circuits (like I'm usually dealing with) aren't particularly dangerous, even if you had soapy or sweaty skin the most they could do is give you a tingle. It'd just be so nice to be able to trace down wiring issues without having to grab a multimeter and probe around to get info. Also it'd be bad ass to grab a battery and be able to tell the voltage.
For sure! I'm usually dealing with things similar to 12vdc car wiring, up to a couple amps at most. As long as your body isn't an easier path to ground than through the conductor itself then you have nothing to worry about. Path of least resistance and all that, and skin is pretty resistive. I have been bitten by an ignition coil before (like 10k+ volts, maybe a few milliamps), that's an experience you never forget. That kind of electricity can jump through the air and give you a proper zap.
edit: the ignition coil was disconnected from the spark plug, leaving the high tension coil ready to find a path to ground any way it can, like through my hand. A bad mistake I hope I can teach people to be aware of.